Conventionally, as an image formation device that receives image data through a network and outputs an image (e.g., print an image on a sheet-type recording medium), a printer, a digital copier and the like have been known. Further, a known image formation system estimates an output cost when an image is printed by the image formation device and compares the estimated value with an available cost to determine whether the image is to be output. An example of such an image formation system is disclosed in Japanese Patent Provisional Publication No. P2001-195224A (hereinafter, referred to as “the '224 publication”), teachings of which are incorporated herein by reference.
In the image formation system disclosed in the '224 publication, if the estimated value is less than the remaining amount of money on the prepaid card, the system allows the output of the image, and executes the charging procedure in which the output cost is subtracted from the remaining amount of money on the prepaid card. If the estimated value exceeds the remaining amount of money on the prepaid card, the system inhibits output of the image.
It should be noted that the charging procedure in this specification includes information processing necessary for determining a price for a service to a user. A payment method for such a price includes settlement using electronic money or a credit card, a prepaid card, and the like which has an effect equivalent to cash payment.
In the conventional image formation system as in the '224 publication, output of the image is controlled such that the image formation device outputs an entire image based on the image data received from an external device (i.e., server device) and the estimated cost and the available output cost (e.g., the remaining amount of money on the prepaid card). Therefore, according to the conventional image formation system, it is difficult to control the system so that the image based on image data corresponding to only a predetermined (desired) amount of money is output by the image formation device.
According to the image formation system configured as above, for example, the following problem arises.
If, for example, the image formation system is for printing out images based on data (e.g., news data) provided by an information source service proprietor, the user of the service may receive unnecessary data (e.g., news data in which the user is not interested). In such a case, according to the conventional system, although the user does not want to, it is impossible to stop printing the news data. In such a case, unnecessary charges for the unnecessary new data are imposed on the user. Further, according to the conventional image formation system, it is impossible for the user to set an allowable amount of money depending on contents/importance of provided information (e.g., in the case of news information, currently occurring accidents/phenomena may be more important than others), so that the user can obtain necessary amount of information.